Timer.



G. T. BROWN.

TIMER. I APPLICATION FILED B13018, 1909.

Patented July 11, 1911 n 0 M V N I i 5 2 2 v v ATTORNEYS I GEORGE TEALLBROWN, OF NEW YORK, N. Y.,

TIMER.

Specification of Letters Patent. Patented July 11, 19] 1.

Application filed December 18, 1909. Serial No. 533,854.

To all whom it may concern: I

Be it known that I, GEORGE T. BROWN, a citizen of the United States, anda resident of the city of New York, borough of Manhattan, in the countyand State of New York, have invented a new and Improved Timer,-of whichthe following is a full,

clear, and exact description.

This 1nvent1on relates-to certain unprovements intimers for use incontrolling the closing of a plurality of electric circuits insuccession, and relates more particularly to the t pe of timer commonlyemployed with the e ectric ignition system of multiple cylinder internalcombustion engines.

The main object of my invention is to so form the timer that the lengthof time durstantially uniform irrespective'of the speed of the engine.

In my improved timer I close the circuit by bringing into engagementwith each other, two contact members, one of which presents a helicalface, and I control the ad vancement or retardation of the'spark byvaryingthe point of engagement along the helical contact face insubstantially the same I erably the latter. is provided-with a bracket15-, by means of which the casing may be der to automatically controlthe length of manner as in my previous Patent, No. 938,208 grantedOctober 26, 1909. In ortime of the contact, I form the face of greaterwidth adjacent one end than adjacent thev other,-so that. as. the pointof contact is moved toward one end of the face and the spark advanced toincrease the speed of the engine, the contact will be made across the'widerportion ofthe face, and this wider portion traveling athi herspeed will give substantially the same length of contact as the narrowerportion traveling at lower speed.

A further object of my invention is to improve the means, for advancingor retarding the time of contact.

Further objects and advantages of my improved construction will be setforth I hereinafter and the invention defined in the claims.

ing drawings, forming a part of this specification. in which similarcharacters of reference indicate corresponding parts in ail 'thefigures,and in which- Figure 1 is a longitudinal section through a timerconstructed in accordance with my I 3, I employ a cylinder casing 10,having one end wall integral therewith and invention and in which therotatable-contact member presents a helical face; Fig. 2. 1s atransverse section on the line 22 of Fig. 1; Fig. 3 is a development ofa portion of the surface of the rotatable contact member shown in Figs.1 and 2; and Fig. 1 is a longltudlnal section similarto Fig. 1, but

showing a form in which the plurality of gines, but it is evident thatthe same novel features of construction might be embodied in devices forother uses, as, for instance, in distributors and in circuit closersgenerallyl ing which the'contact is made, will be sub- In thespecificform shown in Figs. 1 to providing a bearing 11 for a rotatableshaft 12. At the opposite end of the casing, there is provided aremovable wall 13, secured in place 1 by screw threads or in any othersuitable manner and adapted to. be locked against accidental looseningby a locking screw 14. fither the casing or the end wall, butprefrigidly and firmly secured to the engine base or to any othersuitable support. The casing, about its periphery, is providedwith aplurahtyof openings, within whicharesupi ported aplurality of contactmembers-16.

These contact members are spaced-at equal distances apart and correspondin number to the number of engine cylinders. Each, contact member isinsulated from the Wall of the casing in case the latter is not made.

.of insulating material, and each-".co'ntact member preferably carriesat its inner end, fa spring-pressed ball which has a contact I face. Theball is capable of rotationyas it is struck by the movable contactmember vhereinafter described, and is capable crin- ,slight outwardmmement, so that itwill Always make the proper contact and close 1 thecircuit. .I do not claim any special nev Reference is to be had to. theaccompany-.5:

eltyfin the contact member per se, and "do not desire to be limited tothe contact member shown, but in practice I have found. this specificcontact member very efiicient in 0p" 1 eration, I v The shaft 12isjournaledin the opposite;

- end walls of the casing, and. within the ca's-f 11b ing it carries asleeve 17, which engages with the opposite end bearings and positivelyprevents any longitudinal movement of the shaft in respect to thecasing. This sleeve carries a collar 18, which is free to slidelengthwise of the sleeve, but is prevented from rotating in respectthereto by a key 19. The collar is provided with an annular groove 20adjacent one end, and within this groove is disposed a yoke 21 carriedby a rod 22, extending through a hearing in the end wall 13 and parallelto the shaft 12. The rod 22 is capable of longitudinal movement into andout of the casing, and t-heyo-ke 21 is carried thereby, so as to movethe collar 18 lengthwise of the casing. The collar 18 carries a secondcollar .23, which is held rigid in respect thereto by a set screw 24, orother suitable means. This second collar 23, upon its outer surface, hasan outwardly-extending flange 25, presenting a helically-disposedcontact face concentric with the shaft. This contact collar 23 and'itsflange. are electrically connected with the shaft and with the enginebase, while the contacts 16 are connected by separate wires to theinduction coils. As the shaft 12 is rotated at a speed bearing somedefinite relationship to the speed of the engine, the hcli cal contact25 is brought into engagement with the several contacts 16 insuccession, so as to close the several circuits in succession. The shaftbears a. particular angular relationship to the engine shaft, so thatthe helical contact 25 is always in exactly the same position when thepiston of any one engine passes head center, but the time at which thehelical contact engages with any particular contact 16, will depend uponthe lon itudinal dis osition of said helical contact. If the advancedend of the contact 25 be the portion which closes the circuit, then thecir uit will be closed early in the revolution, but if the rear orretarded end of the contact 25 be the portion which closes the circuit,then the circuit will be closed later in the revolution.

All other things being equal, the speed of the engine is largelydependent upon the time of the explosion in respect to the time of theengine piston passing the end of the compression stroke, and the morethe spark is retarded the slower will he the speed of the engine.

0110 of the most important features of my present invention relates tothe means whereby the du *ation of the spark or the duration of timeduring which the circuit is closed, will be substantially constantirrespective of the speed at which the helical contact members pass thestationary contact. In order to render this duration of timesubstantially constant, I make the advanced end of the helical contactof greater width than the rearward end, as is illustrated particularlyin the development in Fig. 3. If the rearward end of the helical contactacts to close the circuit, the engine will be going at a slow rate ofspeed, and there will be a certain definite duration of contact. If theadvanced end of the helical contact serve to close the circuit, theengine will ordinarily be traveling at a much higher speed, and theduration of contact due to the greater width at the advanced end will besubstantially the same as before. Thus, the longitudinal movement of therod 22 operates to advance or retard the spark, and this advancement orretardation serves to increase or decrease the speed of the engine. Thevariation in the speed of the engine varies the speed of rotation of thehelical contact member, so that under substantially all conditions, theduration of contact will be the same.

It is not at all essential that the helical contact member be the onethat rotates, or that the helical contact member be the one which ismoved longitudinally to advance or retard the time of circuit closing.in the form shown in Fig. 4, certain reversals of parts are shown. Inthis form, the casing 10 is similar to the casing above referred to,except that it is formed entirely of insulating material. To the innersurface of this casing, there are secured a plurality of contact members16, which present helicallydisposed surfaces, and which are connected toseparate binding posts 26 extending out through the casing wall. Withinthe casing,

the sleeve 17 carries a collar 2i ca )ablc of longitudinal movement butheld from rotation in respect to the sleeve. This collar is adapted tobe moved longitudinally by a rod 22, the same as the form firstdescribed.

The collar 23 has a radially-disposed socket -tact members. The resultproduced is sub stantially the same as that obtained by the use of theform shown in l igs. 1, 3 and 3.

If it is not desired to operate the timer, for instance when a second orauxiliary ignition systen'i is employed, l. may move the helicalcontactmcmbcr of the form shown in Fig. 1, to one extreme position, sothat no portion of it will engage with the contacts 16. This will permitthe shaft t rotate freely without wear on any of the contacts, andwithout any material retarding effect. I

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

1. A timer for internal combustion engines, comprising a casing adaptedto be rigidly secured in positionl and havinge peripheral Wall and endWalls, a rotatable shaft extending through one of said end Walls intosaid casing and supported by the latter, a collar mounted on said shaftWithin said casing and non-rotatable in respect to said shaft andmovable longitudinally of the casing,-means for shifting said collar, acon 4 tagt carried by said casing and a contact carried by said collar,one of said contacts presenting a helical face, one end of whlch is ofgreater Width than the other end.

2. A timer for internal combustion-engines, comprising a casing adaptedto be rigidly secured in position and having a peripheral wall and endWalls, a rotatable shaft extending through one of said end Wallsinto'the casing and supported by said end Walls, a collar mounted onsaid shaft Within the casing and non-rotatable in respect to said shaftand movable longitudinally of the casing, a rod extending through one ofsaid end Walls adjacent said shaft and substantially parallel to thelatter and having its inner end provided With a yoke in engagement withsaid collar, a plurality of contacts carried by saidcasing, and acontact carried .by said collar, one of said contacts presenting ahelical face, one end of which is of greater Width than'the other.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing Witnesses.

GEORGE TEALL BROWVN. VVitnessesi CLAIR V. FAIRBANK, PHILIP-D. RoLLHAUs.

